Question

which ion has the highest radius​

Answer 1

Because K + has the greatest nuclear charge (Z = 19), its radius is smallest, and S 2− with Z = 16 has the largest radius.

...

Ionic Radii and Isoelectronic Series.

Answer 2

Explanation:

HYY GOOD MORNING

YOUR ANSWER

the coordination environment in the first place as ionic radii are C.N.-dependent. From Shannon's canonical paper "Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides.

⬇️⬇️⬇️⬇️

The data is also available online for free.

Comparing similar coordination environments, it's easier to notice that overall Na+NaX+ is indeed larger than Ca2+.